A group of researchers just reported positive results of a phase 3 trial showing that the addition of radiation therapy (RT) improves overall survival in men with locally advanced prostate cancer (T3 & T4) to androgen deprivation therapy (ADT) alone.

The researchers used a sample of 1,057 men with locally advanced (T3 or T4) prostate cancer or organ-confined prostate cancer (T2) with either a prostate-specific antigen (PSA) concentration more than 40 ng/mL (n=119) or PSA concentration more than 20 ng/mL and a Gleason score of 8 or higher (n=25). The men were randomly assigned to receive lifelong ADT and RT (65—69 Gy to the prostate and seminal vesicles, 45 Gy to the pelvic nodes) or just ADT. The primary endpoint was overall survival.

The results reported are of an interim analysis planned for when two-thirds of the events for the final analysis were recorded. All efficacy analyses were done by intention to treat and were based on data from all patients. This trial is registered at controlledtrials.com as ISRCTN24991896 and Clinicaltrials.gov as NCT00002633.

The Results

1- Between 1995 and 2005, 1205 men were randomly assigned (602 in the ADT only group and 603 in the ADT and RT group); median follow-up was 6·0 years (IQR 4·4—8·0).

2- At the time of analysis, a total of 320 men had died, 175 in the ADT only group and 145 in the ADT and RT group. The addition of RT to ADT improved overall survival at 7 years (74%, 95% CI 70—78 vs 66%, 60—70; hazard ratio [HR] 0·77, 95% CI 0·61—0·98, p=0·033).

3- Both toxicity and health-related quality-of-life results showed a small effect of RT on late gastrointestinal toxicity (rectal bleeding grade >3, three patients (0·5%) in the ADT only group, two (0·3%) in the ADT and RT group; diarrhea grade >3, four patients (0·7%) vs eight (1·3%); urinary toxicity grade >3, 14 patients (2·3%) in both groups).

The addition of RT to ADT in men with locally advanced prostate cancer adds to their overall survival benefit. Men with locally advanced prostate cancer should consider treatment with both ADT and RT. The next step s to determine if ADT on an intermittent schedule would yield similar results.

Funding from: Canadian Cancer Society Research Institute, US National Cancer Institute, and UK Medical Research Council.

Lancet.com, November 201
Dr Padraig Warde MB Malcolm Mason MB , Keyue Ding PhD , Peter Kirkbride MB , Michael Brundage MD, Richard Cowan MB, Mary Gospodarowicz MD, Karen Sanders BSc, Edmund Kostashuk MD, Greg Swanson MD, Jim Barber MB, Andrea Hiltz MSc, Mahesh KB Parmar PhD, Jinka Sathya MB, John Anderson MB, Charles Hayter MD, John Hetherington MB, Matthew R Sydes CStat, Wendy Parulekar MD, for the NCIC CTG PR.3/MRC UK PR07 investigators

Joel T. Nowak, M.A., M.S.W.